The organic EL panel to be used in an organic EL display includes an organic film sandwiched between electrodes, the organic film comprising an organic compound. The organic compound emits light by flowing an electrical current between both electrodes. One of the methods for configuring such an organic EL display as a full-color display is a technique using a color filter system. This type of organic EL display device has been disclosed in, e.g., JP-A-9-212106.
In the technique that uses a color filter system to configure an organic EL display as a full-color display, an organic EL element, which emits white light, is combined with color filter layers of three primary colors to realize a full-color organic EL display. FIG. 9 is a schematic view of a portion of a conventional organic EL display device 2. As shown in FIG. 9, the conventional organic EL display device 2 comprises a glass substrate 201, color filters 202 of RGB (red, green and blue) disposed on the glass substrate, and an overcoat layer 203 disposed on the color filters, the overcoat layer being made of a transparent resin, such as an acrylic resin.
Additionally, the overcoat layer has an inorganic solid layer 204 disposed thereon in order to prevent the organic EL element from being deteriorated by a slight amount of moisture, a solvent or an organic compound contained in the color filters 202 and the overcoat layer 203. The inorganic solid layer has transparent conductive layers (anodes) 205 disposed and patterned thereon, and the inorganic solid layer and the transparent conductive layers are covered with an insulating film 206 having openings formed therein. The insulating film has an organic film 207 deposited thereon so as to emit white light, and the organic film has cathodes 208 disposed thereon. When an electrical current flows between a transparent conductive layer (anode) 205 and a cathode 208, the organic film 207 emits white light. The white light, which has been emitted from the organic film 207, passes through the transparent conductive layer (anode) 205 and a color filter 202 transparent conductive layer (anode) 205. The white light enters a desired one of the color filets 202 of RGB to emit a desired color of R, G or B, configuring the organic EL display device as a full-color display. Each of the layers below the organic film 207, i.e., the transparent conductive layers (anodes) 205, the inorganic solid layer 204, the overcoat layer 203 and the glass substrate 201, is made of a transparent material. The organic EL display device also includes supplemental wires to be connected to the cathodes 208, which are not shown in FIG. 9.
The inorganic solid layer 204 protects the organic EL element from the moisture and/or the organic compound as stated above. The inorganic solid layer plays a quite important role in terms of having an effect on yield. When the inorganic solid layer 204 is incompletely disposed, display characteristics are changed. For example, there has been known a problem that since an organic EL element is deteriorated with the lapse of time after completion of the element, non-luminous portions R are caused as shown in FIG. 10. The inorganic solid layer 204 plays a quite important role to protect an organic layer from moisture and/or an organic compound in the organic EL display device. In FIG. 10, the transparent conductive layers (anodes) 205 shown in FIG. 9 are indicated by dotted lines, and separators 111 for formation of the separated cathodes are disposed so as to extend perpendicular to the cathodes.